Field of the Invention
The invention relates to an image capturing apparatus and an image processing method thereof; more particularly, the invention relates to a light field camera and an image processing method thereof.
Description of Related Art
When a scene to be photographed is characterized by high contrast, e.g., if the scene contains sky with high brightness or dark shadow with low brightness, or if an intense light directly irradiates the lens, the signal intensity of the regions with high brightness may reach or approach a saturated value because the image sensing component of the conventional image capturing apparatus can merely convert an optical signal into an electric signal in a restricted manner while fixed parameters (e.g., exposure time, gain, etc.) are given. To prevent the intensity of the electrical signal in the regions with high brightness from approaching or reaching the saturated value, it is likely to adjust parameters (e.g., the exposure time) of the image sensing component to reduce the intensity of the electrical signal in the regions with high brightness, which however significantly reduces the intensity of the electrical signal in the regions with low brightness and thus results in the fact that the intensity of the electrical signal in the regions with low brightness approximates to the intensity of the noise of the image sensing component. Hence, when the resolution of the image in the regions with high brightness is compromised due to the saturation of the electrical signal in the regions with high brightness, or when the relevant parameters are adjusted in order not to saturate the signal intensity of the regions with high brightness, the intensity of the signal in the regions with low brightness still approximates to the intensity of the noise, and accordingly the resolution of the image in the regions with low brightness is lessened. Although proper hardware or software may be adopted, the resolutions of the images in the regions with high brightness and low brightness cannot be both taken into consideration according to the related art. To resolve the issues described above, a number of methods for ensuring images to have high dynamic range (HDR, also referred to as “wide dynamic range, WDR”) have been proposed.
The information disclosed in this “Description of Related Art” section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Further, the information disclosed in this “Description of Related Art” section does not mean that one or more problems to be resolved by one or more embodiments of the invention were acknowledged by a person of ordinary skill in the art.